Water-compatible urethane-containing amine hardener

ABSTRACT

A formulation to produce urethane linkages reacts cyclocarbonate groups with diamines. Aliphatic polyhydroxyl precursor molecules are first epoxidized. The invention does not require complete epoxidation, as it makes use of the un-epoxidized hydroxyl groups of the precursor molecule. These hydroxyl groups are combined with isocyanate groups of prepolymer molecules to form urethane links. The use of prepolymers increases the networking, flexibility, and impact-resistance of the final product. The known formulations for amine hardeners also require complete carbonation of the epoxy groups to form reactive cyclocarbonate groups, which are reacted with diamines to form an amine hardener. In the proposed invention, both cyclocarbonate and epoxy groups are used to combine with the different diamine molecules by making use of the different reactivities of aliphatic, cycloaliphatic, and aromatic amine groups. This procedure not only increases the networking in the final polyurethane, it ensures that there are enough reactive amines to form the amine hardener. In addition, the resulting urethane contains hydroxyl groups which impart water-compatibility. The amine hardener can then be combined with any commercial epoxy resin to form a polyurethane that is water-compatible, non-toxic, has a low viscosity, and a high degree of penetrance into a surface, and after curing is impact-resistant, abrasion-resistant, chemical-resistant, strong, and flexible.

RELATED APPLICATIONS

This application is a divisional of application 08/876,998 filed on Jun.16, 1997, now U.S. Pat. No. 6,218,480.

FIELD OF THE INVENTION

This invention relates generally to polyurethane formulations. Moreparticularly, it relates to a water-compatible urethane-containing aminehardener which produces a polyurethane when combined with an epoxyresin.

BACKGROUND OF THE INVENTION

Polyurethanes are high molecular weight compounds which have a highdegree of strength, hardness, and friction resistance. They are oftenused as adhesives, cements, and coatings. They are made of polymerswhich contain repeating urethane groups, as shown in FIG. 1.

Traditionally, polyurethanes may be produced by reacting diols withdi-isocyanates, as shown in FIG. 3. U.S. Pat. No. 4,401,499 by Kanekoet. al discloses a method for producing a resin which reacts moleculescontaining hydroxyl groups with di-isocyanates to form temporaryurethane polymers, which are noted for their stability and strength.Isocyanates, however, are highly toxic, non-stable substances becausethey react easily with water, such as moisture in the air. This methodof producing polyurethane cannot be used in many applications, namelythose involving direct contact with water.

U.S. Pat. No. 5,175,231 by Rappoport, incorporated herein by reference,describes a method for producing water-compatible polyurethanes whichinvolves reacting oligomeric cyclocarbonates with diamines. This methodbegins with aliphatic polyepoxy molecules, which are used as precursorsfor cyclocarbonate-containing molecules. An example is Heloxy 84®produced by Shell Chemical Company. This product contains several epoxyfunctional groups. Since a desirable polyurethane coating comprisesmolecules attached to each other in a non-dissipated, three-dimensionalnetwork, it is preferable to have a precursor containing as manymulti-functional epoxy groups as possible. However, the aliphaticpolyepoxy molecules normally contain a number of residual hydroxylgroups that were not converted to epoxy groups, as epoxidation ofaliphatic molecules is never 100% efficient due to the nature of thereaction commonly used. As a result, there are fewer epoxy groupsavailable than desired, thus reducing the number of cyclocarbonategroups and possible links in the future polyurethane network. Althoughit is possible to increase the percentage of epoxy groups, it is moreexpensive and technically difficult to reach comprehensive epoxidationof aliphatic hydroxyl-containing compounds such as Heloxy 84®.

In Rappoport's method, the epoxy functional groups of Heloxy 84® arereacted with carbon dioxide to produce cyclocarbonate functional groups.The reaction is shown in FIG. 2. This reaction is also less than 100%efficient, leaving some epoxy groups unreacted. Like the residualhydroxyl groups mentioned above, these unreacted epoxy groups reduce thefunctionality of the urethane molecule and as a consequence, the numberof links in the final polyurethane network. Typically, the conversionrate of epoxy groups to cyclocarbonate groups is only about 80-85%efficient at the soft conditions before “sticking” of the carbonationreaction occurs. In order to achieve comprehensive carbonation, a moreextreme version of the reaction must be carried out. The temperature israised from 100° C. to 130° C., the reaction time is increased from1-1.5 hours to 5-6 hours, and a larger amount of catalyst, usuallyquaternary ammonium salts, is used. Though this reaction ensures thatnearly all the epoxy groups have been turned into cyclocarbonate groups,it also produces undesirable side reactions and products. In addition,it is more expensive and time-consuming.

After the formation of cyclocarbonate functional groups, the moleculesare reacted with diamines, such as Vestamine IPD (isophorone diamine)and Vestamine TMD (trimethyl hexamethylene diamine), both made by HülsAmerica, Inc. The reaction is shown in FIG. 4. These diamines containtwo amine groups with different reactivities. For the isophoronediamine, the aliphatic amine groups are the more reactive amines, whilethe cycloaliphatic amine groups are the less reactive amines. The morereactive aliphatic amines are usually used to react with thecyclocarbonate groups of the molecules, thus forming urethane links. Theless reactive cycloaliphatic amines are left unreacted. The urethanelinks form the basis for the urethane-containing amine hardener. Theamine hardener is usually packaged and stored until it is time to createthe polyurethane.

In order to create the polyurethane, the urethane-containing moleculesof the amine hardener containing the unreacted less reactivecycloaliphatic amines are combined with an epoxy resin. These lessreactive cycloaliphatic amines react with the epoxy resin to form thepolyurethane. The polyurethane is then cured as a result of thehardener's multifunctionality. Unfortunately, because all the morereactive amine groups have previously reacted, there is often a shortageof less reactive amine groups in the curing stage which leaves thereaction incomplete and weakens the structure of the final polyurethane.

In many epoxide resin-amine hardener formulations, reactions are carriedout in the presence of organic solvents, which are volatile airpollutants and sometimes carcinogenic. These organic solvents alsodecrease the reactivity of the functional groups, thus reducing thedegree of cross-linking.

OBJECTS AND ADVANTAGES OF THE INVENTION

Accordingly, it is the primary object of the present invention toimprove the efficiency and lower the cost of amine hardener formulationsand to overcome problems due to the incomplete epoxidation andcarbonation reactions. It is another object of this invention to providea variety of amine hardeners by formulating different combinations ofthe necessary structural units, which also allows control over theproperties of the polyurethane to be produced. It is another object ofthe invention to remove hazardous components from the presence ofpolyurethane users at the final processing stage. Another object of theinvention is to produce a superior polyurethane formulation, which iswater-compatible, non-toxic, has a low viscosity, and has a high degreeof penetrance into a surface (mainly porous) before curing, and isimpact-resistant, abrasion-resistant, chemical-resistant, strong, andflexible after curing. It is a final object of the invention to providea one-package polyurethane formulation, whereby the urethane-containingamine hardener and epoxy resin can be packaged together for a certainamount of time without reacting until needed.

SUMMARY OF THE INVENTION

These objects and advantages are attained by an improvedurethane-containing amine hardener synthesis. Precursor aliphaticpolyepoxies, such as Heloxy 84®, contain a plurality of epoxy functionalgroups, as well as residual hydroxyl functional groups that were notconverted to epoxy groups at the time of the Heloxy 84® synthesis frompolyepoxy molecules. The proposed formulation for amine hardenersynthesis makes use of the unconverted hydroxyl groups by reacting themwith isocyanate groups on a prepolymer molecule to form aurethane-containing molecule. Although this reaction contains hazardouscomponents, it is achieved under the supervision of specialists insealed chemical equipment. Polyurethane users are not exposed to anychemical hazards.

As a result of the above modification, the epoxy-containing moleculesbearing the mentioned hydroxyl groups are combined together by use ofthe prepolymer molecule. Consequently, the common functionality of themixture is increased and a more complete, non-dissipated,three-dimensional network can be created at the curing stage. As isdescribed in the known method, the epoxy groups are reacted with carbondioxide to form cyclocarbonate groups. If this reaction is carried outat the more soft conditions, it is 80-85% efficient, thus leaving someepoxy groups unconverted. The proposed formulation for amine hardenersis able to make use of the unreacted epoxy groups by taking advantage ofthe different reactivities of diamine molecules, cyclocarbonatemolecules, and epoxy molecules. Aliphatic amines have a high reactivityto both cyclocarbonate and epoxy functional groups, as shown in FIGS. 5and 6. Cycloaliphatic amines have a lower reactivity but are still ableto react with both cyclocarbonate and epoxy functional groups, as shownin FIGS. 7 and 8. Aromatic amines are the least reactive, as they areonly able to react with epoxy functional groups, as shown in FIG. 9, butnot with the cyclocarbonate groups. Thus, selectively reacting thearomatic amine groups with the unconverted epoxy groups on the urethanemolecule renders them functional, but does not affect the cyclocarbonategroups. This reaction produces functional amine-containing moleculeswhich are indifferent to cyclocarbonate groups at the ambienttemperature, so that the two can coexist. However, after the addition ofthe epoxy resin to form the final polyurethane, the aromatic amines willbe able to participate in the curing process.

The different reactivity of the amines is also used in the final stageof urethane-containing amine hardener synthesis. Modified diamines areused instead of the “virgin” ones used in the known method. By blockingthe more reactive aliphatic amine groups of the isophorone diamine witha ketone, thus forming an amino-ketoxime, as shown in FIG. 10, it ispossible to allow the less reactive cycloaliphatic amine groups to reactwith the cyclocarbonate functional groups first.

Interior urethane links are formed in this way. These molecules arestable and can be kept for a certain amount of time until thepolyurethane is produced, due to the “hidden” more reactive aliphaticamine groups. These molecules also contain “hidden” hydroxyl groups nearthe urethane links which impart water-compatibility to the finalhardener as a result of the urethane reaction.

To produce the final amine hardener which can react with an epoxy resin,the more reactive aliphatic amine groups must be deprotected. This iseasily achieved with hydrolysis by water to remove the ketones. Theregenerated more reactive aliphatic amine groups can then react with theepoxy functional groups of the epoxide resins. Any commercial aromaticepoxy resin may be used. In addition, the resulting amine hardener maybe used in combination with other commercial polyamine hardeners such asdi-ethylene-triamine or amino-amides to form amine hardeners withdifferent characteristics.

The final amine hardener can be combined with an epoxy resin to form anespecially water-compatible formulation which possessesimpact-resistance, abrasion-resistance, chemical-resistance, strength,and flexibility after curing. This non-toxic polyurethane has a lowviscosity and a high degree of penetrance into a surface, and as suchcan be used to coat, protect, and repair concrete, cement, wood, gypsum,and other porous surfaces. It can also be used for impregnation andreinforcement. Other uses include water-diluted coatings for wood andwater-borne adhesives for silicate materials. Curing can take place atthe ambient temperature. Polyurethane coatings produced by thisinvention are especially strong and flexible, due to the incorporationof the prepolymer molecules which form additional links in the finalnetwork, as well as increasing the functionality of the amine hardener.

In addition, the ability of this invention to make use of all threecyclocarbonate, epoxy, and hydroxyl functional groups not only increasesthe number of links in the final complete network, but also reduces timeand cost factors in the synthesis of urethane-containing amine hardenersand the processing of amine hardener-epoxy resin formulations.

DESCRIPTION OF THE FIGURES

FIG. 1 shows the chemical structure of a urethane link.

FIG. 2 is a reaction diagram between an epoxy group and carbon dioxideto produce a cyclocarbonate-containing molecule.

FIG. 3 is a reaction diagram between an oligodiol and a di-isocyanate toform a polyurethane. This is the known method.

FIG. 4 is a reaction diagram between a cyclocarbonate group and adiamine molecule to form a water-compatible, hydroxyl-containingpolyurethane without the use of di-isocyanates.

FIG. 5 is a reaction diagram between an aliphatic amine group and acyclocarbonate group to form a urethane linkage.

FIG. 6 is a reaction diagram between an aliphatic amine group and anepoxy group to form a secondary amine linkage.

FIG. 7 is a reaction diagram between a cycloaliphatic amine group and acyclocarbonate group to form a urethane linkage.

FIG. 8 is a reaction diagram between a cycloaliphatic amine group and anepoxy group to form a secondary amine linkage.

FIG. 9 is a reaction diagram between an aromatic diamine and an epoxygroup to form an amine-containing molecule.

FIG. 10 is a reversible reaction diagram between an aliphatic aminegroup and a ketone to form an amino-ketoxime.

DETAILED DESCRIPTION

The proposed formulation for a urethane-containing amine hardener to becombined with an epoxy resin to form a polyurethane begins with analiphatic polyepoxy precursor molecule that typically has not beencompletely epoxidized. This molecule may contain any number of bothepoxy and hydroxyl functional groups. Examples of such a moleculeinclude Heloxy 84® from Shell Chemical Company, or any otherepoxy-containing polyether typically having molecular weight 500-2000,functionality of 2.5-4.0, and containing 10-20% residual hydroxyl groupsafter incomplete epoxidation of corresponding polyhydroxylatedprecursors. The following steps are then carried out:

I. The epoxy functional groups of the aliphatic polyepoxy precursormolecules are reacted with carbon dioxide to form cyclocarbonatefunctional end groups, as shown in FIG. 2. Reaction conditions areroughly at a temperature of 110° C. for 1-1.5 hours, with the additionof a catalyst, usually quaternary ammonium salts. Under these reactionconditions, complete carbonation of the epoxy groups will not occur, sosome epoxy groups will remain unreacted. Efficiency is estimated at80-85%. The resulting product contains both unconverted epoxy andhydroxyl functional groups.

II. The residual hydroxyl functional groups of thecyclocarbonate-containing intermediates are combined with isocyanategroups of isocyanated prepolymer molecules to form urethane molecules,as shown in FIG. 3. By using prepolymer molecules with at least twoisocyanate groups, it is possible to combine two hydroxyl-containing,cyclocarbonate-containing molecules, thus creating a tetra-functionalurethane polymer from two bi-functional molecules. Examples of such aprepolymer molecule include any commercial polymers based on polyethers,polyesters, mixed poly (ethers-esters), or oligodienediols withmolecular weight of 500-2000. This reaction is carried out usingtraditional polyurethane chemistry under controlled conditions bytrained specialists. The polyurethane users are not in any wayassociated with this reaction.

III. The residual epoxy groups of the urethane molecules are madefunctional by combining them with aromatic diamine molecules to formamine-containing urethane molecules. Examples of such aromatic diaminemolecules are methylene-bisorto-aniline and its substituted derivatives.The aromatic amines are relatively unreactive and as such, do not reactwith the cyclocarbonate groups. However, they participate in thereaction with the epoxy groups of the epoxy resin later on.

IV. At this point, the cyclocarbonate groups of the intermediatemolecules are reacted with diamine molecules containing amine groupswith different reactivities to form a functional amine hardener, asshown in FIGS. 5 and 7. An example of such a diamine molecule is anisophorone diamine containing more reactive aliphatic groups and lessreactive cycloaliphatic groups. To create an amine hardener withincreased reactivity, a preliminary modification of the diamine moleculeis made. The more reactive aliphatic amine groups are protected by useof a ketone to produce an amino-ketoxime, as shown in FIG. 10. Anexample of such a ketone is methyl ethyl ketone. The less reactivecycloaliphatic amine groups are left unmodified.

V. The cyclocarbonate functional groups of the urethane molecules arenow able to combine with the unprotected less reactive cycloaliphaticamine groups to form an amine hardener, as shown in FIG. 7. The urethanelinkages produced by the reaction between the cyclocarbonate groups andthe above amines contain hydroxyl groups that impart water-solubilty tothe final polyurethane. The resulting urethane-containing amine hardeneris stable and can be packaged and stored under dry conditions untilneeded.

VI. When it is time to form the final cured polyurethane, the morereactive aliphatic amine groups are regenerated, as shown in FIG. 10.The amino-ketoxime may be hydrolyzed and destroyed by addition of water.A much larger volume of water than neccesary to destroy theamino-ketoxime may be used.

VII. With the addition of an epoxy resin, this amine hardener can nowform the polyurethane. Any commercial aromatic epoxy resin may be used.In addition, the resulting amine hardener may be used in combinationwith other commercial polyamine hardeners such as di-ethylene-triamineor amino-amides to form amine hardeners with different characteristics.

Using the method described above, it is clear that a stable,long-lasting, one-package polyurethane kit can be produced. Such a kitwill contain urethane polymers produced by the described method, anepoxy resin, and a hydrolytic substance. This kit can be stored for afew days under dry conditions and then be transported to the site wherethe polyurethane is to be constructed.

EXAMPLES Example 1

Polyglycidyl ether of an aliphatic polyol with a structure ofpolyoxypropylene, tradename Heloxy 84® (Shell Chemical Company, CASNumber 37237-76-6) having a molecular weight of 620-680 per epoxy group,with a calculated molecular weight approximately of 1700, functionalityequal to 3 according to the chemical formula, with an amount of residualnon-epoxidized hydroxyl groups up to 15%, is used as the main precursorfor the urethane-containing amine hardener synthesis.

500 grams of the above mentioned product are loaded into a microreactorwith a volume of 1 liter, provided with an effective agitator andheater. 1 gram of quaternary ammonium salt catalyst such as n-alkyldi-(methyl)-benzyl ammonium chloride (Mason Chemical Company, TheQuaternary Specialists) or tetra(butyl) ammonium bromide (ZeelandChemicals, Inc.) is added.

Dry carbon dioxide is introduced into the reactor up to a pressure of150 lb/square inch. A temperature of 240° .F is maintained for thecarbonation process.

Periodically, assays from the reactor are analyzed to estimate thedecrease of epoxy groups. Their conversion into carbonate groups iscalculated. After 2 hours, a conversion of 85% is reached.

Example 2

502 grams of the carbonated oligomer as described in EXAMPLE 1 are mixedwith 83.6 grams of an isocyanated prepolymer with a backbone structureof poly(oxytetramethylene), molecular weight appoximately 1,000,containing 7.8% isocyanate groups, tradename Andur 75-DCP-2 (AndersonDevelopment Company). 0.4 grams of di-butyl-di-octate of tin are addedas a catalyst. The reaction between the two components is carried out at120° F. for 2 hours until the content of isocyanate groups is close tozero.

157.4 grams of tri-methyl-hexamethylene diamine (80% solution in water),tradename Vestamin TMD (Hüls America) is mixed with the intermediateabove. The reaction is carried out at 100° F. for 1 hour.

The resulting urethane-containing amine hardener has the followingproperties:

% amine groups: 4.8

viscosity (Brookfield, 50° F.): 800 poises (2 rpm)

The hardener can be mixed with 10% water for a transparent mixtureformation.

Example 3

230 grams of the amine hardener described in EXAMPLE 2 are mixed with100 grams of an aromatic epoxide resin with Epoxide Number 190,tradename Epon 828 (Shell Chemical Company) at the ambient temperature.20 grams of water are added. The mixture of hardener, Epon 828, andwater is transparent. It can penetrate into concrete to a depth of 2-4mm, depending on the type of concrete.

The mixture is left at the ambient temperature for 24 hours. After thefirst 2 hours, the mixture begins to harden.

Testing of the hardened samples is made after 7 days. The cured polymerhas the following properties:

hardness (shore A/D): 75/24

adhesion to concrete: >600 p.s.i.

tensile strength: 1400 p.s.i.

elongation at the break: 67%

flexural modulus: 4800 p.s.i.

Chemicals immersion test—% weight gain after 24 hours at 50° F.:

water: 0.8

10% sulfuric acid: 1.2

50% sodium hydroxide: 0.07

20% sodium chloride: 0.9

methyl ethyl ketone: 38.9

toluene: 18.5

mineral oil: 0.27

Example 4

124 grams of the hardener described in EXAMPLE 2 are mixed with 5.4grams of the commercial hardener di-ethylene-triamine (DETA, BASF Corp.)and then with 90 grams of Epon 828 and 10 grams of Heloxy 48® (both fromShell Chemical Company).

After complete curing at the ambient temperature for 7 days, the finalproduct has the following properties:

hardness (Shore D): 55

tensile strength: 1500 p.s.i.

elongation: 35%

Young's modulus: 11 k.s.i.

flexural modulus: 20500 p.s.i.

Example 5

As in EXAMPLE 4, 83 grams of urethane-containing amine hardener, 7.3grams of DETA, and 90/100 grams of Epon 828/Heloxy 48® are combined.

The cured polymer has the following properties:

hardness (Shore D): 70

adhesion to concrete: >600 p.s.i.

tensile strength: 2700 p.s.i.

elongation: 26%

Young's modulus: 46 k.s.i.

flexural modulus: 73500 p.s.i.

Example 6

A polymer is made by mixing the same components as in the previousexample, using the following masses: 46, 8.7, 90, 10.

The cured polymer has the following properties:

hardness (Shore D):82

adhesion to concrete: >600 p.s.i.

tensile strength: 4500 p.s.i.

elongation: 13%

Young's modulus: 100 k.s.i.

flexural modulus: 145000 p.s.i.

Example 7

A polymer is made by mixing the same components as in the previousexample, using the following masses: 38, 9.1, 90, 10.

The cross-linked polymer has the following properties:

hardness (Shore D): 82

adhesion to concrete: >600 p.s.i.

tensile strength: 4800 p.s.i.

elongation: 15%

Young's modulus: 120 k.s.i.

flexural modulus: 170000 p.s.i.

Example 8

76 grams of the same urethane-containing amine hardener and 23 grams ofthe commercial hardener Jeffamine 230 (Huntsman Corp.) are reacted incombination with an epoxy mixture consisting of 90 grams Epon 828 and 10grams Heloxy 48®.

After curing the polymer has the following properties:

hardness (Shore D): 70

tensile strength: 2630 p.s.i.

elongation: 60%

Young's modulus: 55 k.s.i.

flexural modulus: 70000 p.s.i.

Example 9

The mixture of hardeners described in the previous example consisting of46/28 grams is used in combination with the same amount of epoxies.

The cured polymer has the following properties:

hardness (Shore D): 78

adhesion to concrete: >600 p.s.i.

tensile strength: 4000 p.s.i.

Young's modulus: 110 k.s.i.

flexural modulus: 175000 p.s.i.

Example 10

The mixture of hardeners described in the previous example consisting of32/30 grams is used in combination with the same amount of epoxies.

The cured polymer has the following properties:

hardness (Shore D): 82

adhesion to concrete: 5500 p.s.i.

elongation: 12%

Young's modulus: 160 k.s.i.

flexural modulus: 222000 p.s.i.

Example 11

89.4 grams of carbonated Heloxy 84® made as described in EXAMPLE 1 aremixed with 14.3 grams of isocyanated prepolymer Andur-2-90 AP, molecularweight approximately 2200, containing 4.15% isocyanate groups (AndersonDevelopment Co.)

0.06 grams of tin organic catalyst is added to the mixture. Afterinteraction at 120° C. for 2 hours, no isocyanate groups are detected inthe intermediate product. The product is then mixed with 58.6 grams ofisophorone diamine (80% solution in water), tradename Vestamin IPD (HülsAmerica).

After 1 hour at 120° F. the hardener has a viscosity of 530 poises (at50° F.) and contains 4.26% amine groups.

Example 12

100 grams of urethane-containing amine hardener are made according toEXAMPLE 11 and mixed with 100 grams of Epon 828 and cured at the ambienttemperature.

Solidification occurs after approximately 3.5 hours.

The cured polymer has the following properties:

hardness (Shore D): 83

adhesion to concrete: >600 p.s.i.

tensile strength: 4300 p.s.i.

elongation: 15%

Chemicals immersion test—% weight gain after 24 hours, 50° F.:

water: 0.49

10% sulfuric acid: 0.8

50% sodium hydroxide: 0.23

20% sodium chloride: 0.38

toluene: 4.0

mineral oil: 0.2

Example 13

Heloxy 84® is carbonated as in the procedure described in EXAMPLE 1, butonly up to 73% conversion of epoxy groups. 76 grams of the product aremixed with 11.5 grams of aromatic diamine, tradename Lonzacure M-CDEA(Lonza). After 4 hours at 160° F., analysis shows an absence of theepoxy groups.

The resulting product is reacted with 34.6 grams of Vesamin IPD (80%solution in water) at 120° F. for 2 hours.

The amine hardener has the following properties:

% amine groups: 3.5

viscosity: 530 poises

Example 14

80 grams of hardener made according to EXAMPLE 13 are mixed with 100grams of Epon 828.

After complete curing at the ambient temperature for 7 days, the finalproduct has the following properties:

hardness (Shore D): 80

tensile strength: 1500 p.s.i.

elongation: 35%

Young's modulus: 29 k.s.i.

flexural modulus: 7000 p.s.i.

Chemicals immersion test:

water: 0.45

10% sulfuric acid: 0.8

50% sodium hydroxide: 0.25

20% sodium chloride: 0.25

toluene: 23.0

mineral oil: 0.17

Example 15

64.7 grams of oligomer with 73% carbonation of epoxy groups is reactedwith 10.2 grams of Lonzacure M-CDEA. 29.2 grams of Vestamin TMD (80%aqueous solution) are added.

The complete urethane-containing amine hardener has the followingproperties:

% amine groups: 3.5

viscosity: 85 poises

Example 16

A Heloxy 84® with 90% carbonation of epoxy groups is produced by usingthe procedure of EXAMPLE 1 with the reaction time increased to 5.5hours. 84.7 grams of the obtained product are mixed with 14 grams of theisocyanated prepolymer Andur 2-90 AP and 0.06 grams of tin catalyst.After the isocyanate groups disappeared, 54.2 grams of Vestamin TMD (80%aqueous solution) were added and reacted according to the describedconditions.

The amine hardener has the following properties:

% amine groups: 4

viscosity: 75 poises.

Example 17

100 grams of hardener made accoring to EXAMPLE 16 were mixed with 100grams of Epon 828 and cured completely at the ambient temperature for 7days.

The polymer has the following properties:

hardness (Shore D): 70

tensile strength: 2700 p.s.i.

elongation: 40%

flexural modulus: 44500 p.s.i.

This polymer possesses excellent stability despite UV radiation andremains colorless 6 months after exposure to sun radiation. A fewcommercial formulations made with Epon 828 have turned an intense yellowcolor under the same conditions.

Chemicals immersion test:

water: 0.6

10% sulfuric acid: 1.2

50% sodium hydroxide: 0.35

20% sodium chloride: 0.4

methyl ethyl ketoe: 28.0

toluene: 6.0

mineral oil: 0.09

Example 18

Isophorone diamine (Vestamin IPD) is reacted with methyl ethyl ketone toform an amino-ketoxime. 34 grams of the above diamine are placed in asealed reactor under dry conditions (under argon atmosphere) and cooledto a temperature of approximately 40° F. 15 grams of methyl ethyl ketoneare dosed into the diamine gradually, by separate drops, to avoid a risein temperature. After methyl ethyl ketone dosing, the product of thereaction has been exposed to the ambient temperature for 1 hour. Theurethane-containing amine hardener is synthesized under the conditionsof EXAMPLE 11, but 85 grams of amino-ketoxime is used instead of theindividual dosing of Vestamin IPD. This interaction requires 2.5 hours.The hardener with hidden reactive amine groups has a viscosty of 150poises.

Example 19

105 grams of the hardener of EXAMPLE 18 are mixed with 100 grams of Epon828. This reactive mixture is stored in a sealed vessel at ambienttemperature. No essential change in viscosity is found after 3 days ofstorage. 2 grams of water are added to 100 grams of the reactive mixtureand carefully remixed. Solidification is detected after 1 hour.

What is claimed is:
 1. A method of preparing a water-compatibleurethane-containing amine hardener comprising the steps of: a) producingcyclocarbonate-containing, hydroxyl-containing, epoxy-containingintermediate molecules by reacting carbon dioxide with aliphaticepoxy-containing, hydroxyl-containing molecules; b) producing urethanelinked intermediate molecules by reacting said intermediate moleculeswith isocyanate-containing prepolymer molecules; and c) producing saidamine hardener by reacting said urethane linked intermediate moleculeswith diamine molecules.
 2. The method of claim 1, whereby said urethanelinked intermediate molecules are produced by reacting hydroxyl groupsof said intermediate molecules with said isocyanate-containingprepolymer molecules at a ratio of 1 hydroxyl group: 1 isocyanate groupat 50-60° C. in the presence of 0.01-0.1% catalysts, selected fromorganic tin compounds or tertiary amines.
 3. The method of claim 1,wherein said urethane linked intermediate molecules comprise atetra-functional urethane polymer.
 4. The method of claim 1, wherebysaid step a) occurs at 105-110° C. for 1-2 hours in the presence ofcatalysts, selected from quaternary ammonium salts amounting to 0.1-0.5%of the mass, allowing 80-85% conversion of epoxy groups tocyclocarbonate groups.
 5. An amine hardener made according to the methodof claim
 1. 6. The method of claim 1, wherein said step c) furthercomprises the step of producing amine-containing urethane molecules byreacting epoxy groups of said urethane linked intermediate moleculeswith aromatic diamine molecules.
 7. The method of claim 6 whereby saidreaction is carried out at a ratio of 1 epoxy group:2 aromatic aminegroups.
 8. The method of claim 1, wherein said step c) further comprisesthe step of reacting cyclocarbonate groups of said urethane linkedintermediate molecules with diamine molecules containing amine groupswith different reactivities.
 9. The method of claim 8, wherein saiddiamine molecules contain more reactive aliphatic amine groups and lessreactive cycloaliphatic amine groups.
 10. The method of claim 9, furthercomprising the step of temporarily blocking said more reactive aliphaticamine groups from being reactive by forming an amino-ketoxime with aketone, wherein said less reactive cycloaliphatic amine groups remainreactive.
 11. The method of claim 10, wherein said diamine molecules areisophorone diamine molecules or trimethyl hexamethylene diaminemolecules, and said ketone is a methyl-ethyl ketone.
 12. The method ofclaim 10, further comprising the step of producing urthane links byreacting said less reactive cycloaliphatic amine groups withcyclocarbonate groups of said urethane linked intermediate molecules.13. The method of claim 12, wherein said step of producing urethanelinks uses the ratio of 1 less reactive cycloaliphatic amine group: 1cyclocarbonate group, under dry conditions at a temperature of no morethan 50° C.
 14. The method of claim 10, further comprising the step ofregenerating said aliphatic amine groups by reacting said amino-ketoximewith water such that said amino-ketoxime is hydrolyzed and destroyed.